Annual report pursuant to Section 13 and 15(d)

Summary of Significant Accounting Policies - Additional Information (Details)

Summary of Significant Accounting Policies - Additional Information (Details) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020 USD ($) shares	Sep. 30, 2020 USD ($) shares	Jun. 30, 2020 USD ($) shares	Mar. 31, 2020 USD ($) shares	Dec. 31, 2019 USD ($) shares	Sep. 30, 2019 USD ($) shares	Jun. 30, 2019 USD ($) shares	Mar. 31, 2019 USD ($) shares	Dec. 31, 2020 USD ($) segment item shares	Dec. 31, 2019 USD ($) shares	Dec. 31, 2018 USD ($) shares
Summary Of Significant Accounting Policies [Line Items]
Number of operating segment \| segment									1
Number of financial instruments with off-balance sheet risk \| item									0
Depreciation									$ 2,774	$ 2,521	$ 1,604
Impairment losses									0	0	0
Revenue	$ 5,698	$ 3,828	$ 3,188	$ 2,379	$ 508	$ 558	$ 462	$ 454	$ 15,093	$ 1,982	$ 2,050
Warrant issued to purchase common stock \| shares	2,117,094				2,118,094				2,117,094	2,118,094
Weighted-average number of common shares used in net loss per share applicable to common stockholders - basic and diluted \| shares	48,774,598	45,781,638	45,699,277	43,923,999	42,885,208	42,439,338	41,673,275	33,766,333	46,051,617	40,222,182	32,656,237
ASU 2018-18
Summary Of Significant Accounting Policies [Line Items]
Change in accounting principle, accounting standards update, adopted	true								true
Change in accounting principle, accounting standards update, adoption date	Jan. 01, 2020								Jan. 01, 2020
Change in accounting principle, accounting standards update, immaterial effect	true								true
ASU 2018-13
Summary Of Significant Accounting Policies [Line Items]
Change in accounting principle, accounting standards update, adopted	true								true
Change in accounting principle, accounting standards update, adoption date	Jan. 01, 2020								Jan. 01, 2020
Change in accounting principle, accounting standards update, immaterial effect	true								true
Private Placement
Summary Of Significant Accounting Policies [Line Items]
Warrant issued to purchase common stock \| shares	2,828,125								2,828,125
Pre-Funded Warrant \| Private Placement
Summary Of Significant Accounting Policies [Line Items]
Warrant issued to purchase common stock \| shares	1,000,000								1,000,000
Performance-based stock options \| Executive Officers
Summary Of Significant Accounting Policies [Line Items]
Compensation expense recognized period									6 years
Global Blood Therapeutics
Summary Of Significant Accounting Policies [Line Items]
Revenue									$ 11,700
Incyte
Summary Of Significant Accounting Policies [Line Items]
Revenue									3,400	$ 2,000	$ 2,100
Construction in progress
Summary Of Significant Accounting Policies [Line Items]
Depreciation									$ 0